Excerpt from the game's official site:
"Federal year 563, a problem occurred when virus penetrated into the central computer. The virus, which penetrated into the central computer was turned out to be the Delta, which was Black angel, presumed to be dead 500 years ago. And they penetrated into the people's mind who were living in the virtual space. And they erupt a war against the human being. The Federal military, which was controlled by the central computer, got totally wiped out recklessly, and rest of the survivors was managed to escape to the Polar Regions. Soon, people began to gather at the polar regions after finding out that the chip in their brains controlled by the computer could not be reached in the cold regions as well. Within 3 years, Deltas subjugated the earth and call themselves 'Createse', who became a new owner of the earth.
Delta found out that Buraman who predicted about the chaos of the earth 500 years ago, was a lineage from the identical twins. After realizing that Buraman's direct lineage had settled in Eol Sha planet of Colduran nebula, Delta dispatched fleets to the planet. Firstly, the Createse subjugated 4
nebulas and began to expand their territory. But the Createse's power got weakened
by strange magnetic wave surrounded in Coldura. So the Createse quickly returned
to the earth. The Intelion, who was successfully defeated themselves against the
Createse, started heading to the earth.
The last lineage of the human-being on earth, the Hominian, which
was expanding their territory while hiding themselves in the
polar region, manipulated themseves as cyborg to avoid
Delta's computer threat. The Hominian used the
opportunity when the Createse and the Intelion were
engaged in a war, which brought weakness of the both
sides. And the Hominian escaped to the another space
while leaving a small number of troops in the polar region.
The war between the Createse and the Intelion
continued to another 50 years. Whereas, the
Createse invented a mutated generic creature to
get out of the regions they used to live. So the
Createse were able to make up their weak point
and began to attack Delta's 003 planet,
which was the main source of Calosoid mineral
in the outer space where the Intelion was
positioned. At the same time, the Hominian
that was launching guerrilla warfare while
hiding them in the Polar Regions began to
attack the Createse with the joint operation
with the other Hominian in the space.
Therefore, 390 in Createse years, final
battle began among the Intelion, the
Createse and the Hominian, and this is
called 'Atrox War', which brought a
great impact in the space history.